With the increase of technology development and demand for a mobile device, demand for a secondary battery as energy source rapidly increases. A nickel-cadmium battery or a hydrogen ion battery was used as a related secondary battery, but a lithium ion battery and a polymer lithium ion battery having high energy density have been more widely used recently.
As a positive electrode active material of such secondary battery, remarkably highlighted is a lithium secondary battery with greater output and capacity compared to weight that uses lithium transition metal oxide, lithium complex oxide, and so on. Generally, the lithium secondary battery is composed of a structure in which an electrode assembly of a positive electrode/separator/negative electrode structure, together with an electrolyte are embedded in a sealed container.
Meanwhile, the lithium secondary battery is composed of a positive electrode, a negative electrode, a separator interposed therebetween, and the electrolyte. Further, the lithium secondary battery may be categorized into the lithium ion battery (LIB), the polymer lithium ion battery (PLIB), and so on according to which materials are used for a positive electrode active material and a negative electrode active material. In a related art, the electrode of the lithium secondary battery may be formed by coating the positive electrode or negative electrode active material on a current collector such as aluminum or copper sheet, mesh, film, foil, and so on, and drying the same.
Generally, in a secondary battery module, a slave form of BMS is provided at a module side to provide data regarding voltage/temperature of each cell, and in an example of an automobile secondary battery pack, a master form of BMS is provided on an upper end such as PCS or EMM to generally manage the overall functions of an entire secondary battery pack.
Further, in an example of a secondary battery module for use as an energy storage system (ESS), for series/parallel scalability between modules, the secondary battery module is formed in such a configuration that a master form of BMSs is provided between separate modules for balancing of the separate modules, and the corresponding data, i.e., the data of each of the slave BMSs is delivered to the master BMS at the uppermost end by using the daisy chain form.
According to a related art, because the secondary battery modules are variously suggested, and configurations and positions of a cartridge constructing a module and a bus bar for sensing are different from each other, an efficient coupling process is difficult to be implemented and welding quality of the sensing structures is lowered. Further, because unnecessary dimensional area of the secondary battery module is provided for a process such as welding, energy density of the secondary battery module may deteriorate ultimately.
Further, the secondary battery module used in an energy storage system or a power storage system puts a focus on the technology development of configuring the secondary battery module to be most compact for the heightened energy efficiency or density.